The strain of bovine tuberculosis detected in a British Columbia cow has not previously been documented in Canada or the United States, says Canada's Chief Veterinary Officer Jaspinder Komal. All of the cows in the herd were tested, and three others had the
same strain of TB.

The Canadian Food Inspection Agency says the animals did not enter the food chain and there was no risk to human health.

The agency has traced the movements of animals that entered or left the infected herd in the past five years and movement controls have been placed on about 18,000 animals in B.C., Alberta and Saskatchewan.

As the investigation continues, movement controls on the herds will fluctuate, Komal said.

Canada is considered officially free of bovine TB although the statement says isolated cases may occur.

Exposure can only occur through the passage of fluids from an animal to an open skin sore, extended close contact with an animal with active respiratory tuberculosis or by drinking unpasteurized milk from an infected animal.

Six cases of bovine TB were identified in cattle from a single Alberta farm in 2016, leading to tests of 34,000 animals from 145 farms.

Those tests showed the disease did not spread from the original farm and international shipments of Canadian beef were never interrupted.

Investigation updates and movement of herds will be posted on the food inspection agency website.